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1 | /* | |
2 | * Copyright (C) 2005-2007 Kristian Hoegsberg <krh@bitplanet.net> | |
3 | * | |
4 | * This program is free software; you can redistribute it and/or modify | |
5 | * it under the terms of the GNU General Public License as published by | |
6 | * the Free Software Foundation; either version 2 of the License, or | |
7 | * (at your option) any later version. | |
8 | * | |
9 | * This program is distributed in the hope that it will be useful, | |
10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
12 | * GNU General Public License for more details. | |
13 | * | |
14 | * You should have received a copy of the GNU General Public License | |
15 | * along with this program; if not, write to the Free Software Foundation, | |
16 | * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. | |
17 | */ | |
18 | ||
19 | #include <linux/bug.h> | |
20 | #include <linux/completion.h> | |
21 | #include <linux/crc-itu-t.h> | |
22 | #include <linux/device.h> | |
23 | #include <linux/errno.h> | |
24 | #include <linux/firewire.h> | |
25 | #include <linux/firewire-constants.h> | |
26 | #include <linux/jiffies.h> | |
27 | #include <linux/kernel.h> | |
28 | #include <linux/kref.h> | |
29 | #include <linux/list.h> | |
30 | #include <linux/module.h> | |
31 | #include <linux/mutex.h> | |
32 | #include <linux/spinlock.h> | |
33 | #include <linux/workqueue.h> | |
34 | ||
35 | #include <asm/atomic.h> | |
36 | #include <asm/byteorder.h> | |
37 | ||
38 | #include "core.h" | |
39 | ||
40 | int fw_compute_block_crc(__be32 *block) | |
41 | { | |
42 | int length; | |
43 | u16 crc; | |
44 | ||
45 | length = (be32_to_cpu(block[0]) >> 16) & 0xff; | |
46 | crc = crc_itu_t(0, (u8 *)&block[1], length * 4); | |
47 | *block |= cpu_to_be32(crc); | |
48 | ||
49 | return length; | |
50 | } | |
51 | ||
52 | static DEFINE_MUTEX(card_mutex); | |
53 | static LIST_HEAD(card_list); | |
54 | ||
55 | static LIST_HEAD(descriptor_list); | |
56 | static int descriptor_count; | |
57 | ||
58 | static __be32 tmp_config_rom[256]; | |
59 | /* ROM header, bus info block, root dir header, capabilities = 7 quadlets */ | |
60 | static size_t config_rom_length = 1 + 4 + 1 + 1; | |
61 | ||
62 | #define BIB_CRC(v) ((v) << 0) | |
63 | #define BIB_CRC_LENGTH(v) ((v) << 16) | |
64 | #define BIB_INFO_LENGTH(v) ((v) << 24) | |
65 | #define BIB_BUS_NAME 0x31333934 /* "1394" */ | |
66 | #define BIB_LINK_SPEED(v) ((v) << 0) | |
67 | #define BIB_GENERATION(v) ((v) << 4) | |
68 | #define BIB_MAX_ROM(v) ((v) << 8) | |
69 | #define BIB_MAX_RECEIVE(v) ((v) << 12) | |
70 | #define BIB_CYC_CLK_ACC(v) ((v) << 16) | |
71 | #define BIB_PMC ((1) << 27) | |
72 | #define BIB_BMC ((1) << 28) | |
73 | #define BIB_ISC ((1) << 29) | |
74 | #define BIB_CMC ((1) << 30) | |
75 | #define BIB_IRMC ((1) << 31) | |
76 | #define NODE_CAPABILITIES 0x0c0083c0 /* per IEEE 1394 clause 8.3.2.6.5.2 */ | |
77 | ||
78 | static void generate_config_rom(struct fw_card *card, __be32 *config_rom) | |
79 | { | |
80 | struct fw_descriptor *desc; | |
81 | int i, j, k, length; | |
82 | ||
83 | /* | |
84 | * Initialize contents of config rom buffer. On the OHCI | |
85 | * controller, block reads to the config rom accesses the host | |
86 | * memory, but quadlet read access the hardware bus info block | |
87 | * registers. That's just crack, but it means we should make | |
88 | * sure the contents of bus info block in host memory matches | |
89 | * the version stored in the OHCI registers. | |
90 | */ | |
91 | ||
92 | config_rom[0] = cpu_to_be32( | |
93 | BIB_CRC_LENGTH(4) | BIB_INFO_LENGTH(4) | BIB_CRC(0)); | |
94 | config_rom[1] = cpu_to_be32(BIB_BUS_NAME); | |
95 | config_rom[2] = cpu_to_be32( | |
96 | BIB_LINK_SPEED(card->link_speed) | | |
97 | BIB_GENERATION(card->config_rom_generation++ % 14 + 2) | | |
98 | BIB_MAX_ROM(2) | | |
99 | BIB_MAX_RECEIVE(card->max_receive) | | |
100 | BIB_BMC | BIB_ISC | BIB_CMC | BIB_IRMC); | |
101 | config_rom[3] = cpu_to_be32(card->guid >> 32); | |
102 | config_rom[4] = cpu_to_be32(card->guid); | |
103 | ||
104 | /* Generate root directory. */ | |
105 | config_rom[6] = cpu_to_be32(NODE_CAPABILITIES); | |
106 | i = 7; | |
107 | j = 7 + descriptor_count; | |
108 | ||
109 | /* Generate root directory entries for descriptors. */ | |
110 | list_for_each_entry (desc, &descriptor_list, link) { | |
111 | if (desc->immediate > 0) | |
112 | config_rom[i++] = cpu_to_be32(desc->immediate); | |
113 | config_rom[i] = cpu_to_be32(desc->key | (j - i)); | |
114 | i++; | |
115 | j += desc->length; | |
116 | } | |
117 | ||
118 | /* Update root directory length. */ | |
119 | config_rom[5] = cpu_to_be32((i - 5 - 1) << 16); | |
120 | ||
121 | /* End of root directory, now copy in descriptors. */ | |
122 | list_for_each_entry (desc, &descriptor_list, link) { | |
123 | for (k = 0; k < desc->length; k++) | |
124 | config_rom[i + k] = cpu_to_be32(desc->data[k]); | |
125 | i += desc->length; | |
126 | } | |
127 | ||
128 | /* Calculate CRCs for all blocks in the config rom. This | |
129 | * assumes that CRC length and info length are identical for | |
130 | * the bus info block, which is always the case for this | |
131 | * implementation. */ | |
132 | for (i = 0; i < j; i += length + 1) | |
133 | length = fw_compute_block_crc(config_rom + i); | |
134 | ||
135 | WARN_ON(j != config_rom_length); | |
136 | } | |
137 | ||
138 | static void update_config_roms(void) | |
139 | { | |
140 | struct fw_card *card; | |
141 | ||
142 | list_for_each_entry (card, &card_list, link) { | |
143 | generate_config_rom(card, tmp_config_rom); | |
144 | card->driver->set_config_rom(card, tmp_config_rom, | |
145 | config_rom_length); | |
146 | } | |
147 | } | |
148 | ||
149 | static size_t required_space(struct fw_descriptor *desc) | |
150 | { | |
151 | /* descriptor + entry into root dir + optional immediate entry */ | |
152 | return desc->length + 1 + (desc->immediate > 0 ? 1 : 0); | |
153 | } | |
154 | ||
155 | int fw_core_add_descriptor(struct fw_descriptor *desc) | |
156 | { | |
157 | size_t i; | |
158 | int ret; | |
159 | ||
160 | /* | |
161 | * Check descriptor is valid; the length of all blocks in the | |
162 | * descriptor has to add up to exactly the length of the | |
163 | * block. | |
164 | */ | |
165 | i = 0; | |
166 | while (i < desc->length) | |
167 | i += (desc->data[i] >> 16) + 1; | |
168 | ||
169 | if (i != desc->length) | |
170 | return -EINVAL; | |
171 | ||
172 | mutex_lock(&card_mutex); | |
173 | ||
174 | if (config_rom_length + required_space(desc) > 256) { | |
175 | ret = -EBUSY; | |
176 | } else { | |
177 | list_add_tail(&desc->link, &descriptor_list); | |
178 | config_rom_length += required_space(desc); | |
179 | descriptor_count++; | |
180 | if (desc->immediate > 0) | |
181 | descriptor_count++; | |
182 | update_config_roms(); | |
183 | ret = 0; | |
184 | } | |
185 | ||
186 | mutex_unlock(&card_mutex); | |
187 | ||
188 | return ret; | |
189 | } | |
190 | EXPORT_SYMBOL(fw_core_add_descriptor); | |
191 | ||
192 | void fw_core_remove_descriptor(struct fw_descriptor *desc) | |
193 | { | |
194 | mutex_lock(&card_mutex); | |
195 | ||
196 | list_del(&desc->link); | |
197 | config_rom_length -= required_space(desc); | |
198 | descriptor_count--; | |
199 | if (desc->immediate > 0) | |
200 | descriptor_count--; | |
201 | update_config_roms(); | |
202 | ||
203 | mutex_unlock(&card_mutex); | |
204 | } | |
205 | EXPORT_SYMBOL(fw_core_remove_descriptor); | |
206 | ||
207 | static void allocate_broadcast_channel(struct fw_card *card, int generation) | |
208 | { | |
209 | int channel, bandwidth = 0; | |
210 | ||
211 | fw_iso_resource_manage(card, generation, 1ULL << 31, &channel, | |
212 | &bandwidth, true, card->bm_transaction_data); | |
213 | if (channel == 31) { | |
214 | card->broadcast_channel_allocated = true; | |
215 | device_for_each_child(card->device, (void *)(long)generation, | |
216 | fw_device_set_broadcast_channel); | |
217 | } | |
218 | } | |
219 | ||
220 | static const char gap_count_table[] = { | |
221 | 63, 5, 7, 8, 10, 13, 16, 18, 21, 24, 26, 29, 32, 35, 37, 40 | |
222 | }; | |
223 | ||
224 | void fw_schedule_bm_work(struct fw_card *card, unsigned long delay) | |
225 | { | |
226 | fw_card_get(card); | |
227 | if (!schedule_delayed_work(&card->work, delay)) | |
228 | fw_card_put(card); | |
229 | } | |
230 | ||
231 | static void fw_card_bm_work(struct work_struct *work) | |
232 | { | |
233 | struct fw_card *card = container_of(work, struct fw_card, work.work); | |
234 | struct fw_device *root_device; | |
235 | struct fw_node *root_node; | |
236 | unsigned long flags; | |
237 | int root_id, new_root_id, irm_id, local_id; | |
238 | int gap_count, generation, grace, rcode; | |
239 | bool do_reset = false; | |
240 | bool root_device_is_running; | |
241 | bool root_device_is_cmc; | |
242 | ||
243 | spin_lock_irqsave(&card->lock, flags); | |
244 | ||
245 | if (card->local_node == NULL) { | |
246 | spin_unlock_irqrestore(&card->lock, flags); | |
247 | goto out_put_card; | |
248 | } | |
249 | ||
250 | generation = card->generation; | |
251 | root_node = card->root_node; | |
252 | fw_node_get(root_node); | |
253 | root_device = root_node->data; | |
254 | root_device_is_running = root_device && | |
255 | atomic_read(&root_device->state) == FW_DEVICE_RUNNING; | |
256 | root_device_is_cmc = root_device && root_device->cmc; | |
257 | root_id = root_node->node_id; | |
258 | irm_id = card->irm_node->node_id; | |
259 | local_id = card->local_node->node_id; | |
260 | ||
261 | grace = time_after(jiffies, card->reset_jiffies + DIV_ROUND_UP(HZ, 8)); | |
262 | ||
263 | if (is_next_generation(generation, card->bm_generation) || | |
264 | (card->bm_generation != generation && grace)) { | |
265 | /* | |
266 | * This first step is to figure out who is IRM and | |
267 | * then try to become bus manager. If the IRM is not | |
268 | * well defined (e.g. does not have an active link | |
269 | * layer or does not responds to our lock request, we | |
270 | * will have to do a little vigilante bus management. | |
271 | * In that case, we do a goto into the gap count logic | |
272 | * so that when we do the reset, we still optimize the | |
273 | * gap count. That could well save a reset in the | |
274 | * next generation. | |
275 | */ | |
276 | ||
277 | if (!card->irm_node->link_on) { | |
278 | new_root_id = local_id; | |
279 | fw_notify("IRM has link off, making local node (%02x) root.\n", | |
280 | new_root_id); | |
281 | goto pick_me; | |
282 | } | |
283 | ||
284 | card->bm_transaction_data[0] = cpu_to_be32(0x3f); | |
285 | card->bm_transaction_data[1] = cpu_to_be32(local_id); | |
286 | ||
287 | spin_unlock_irqrestore(&card->lock, flags); | |
288 | ||
289 | rcode = fw_run_transaction(card, TCODE_LOCK_COMPARE_SWAP, | |
290 | irm_id, generation, SCODE_100, | |
291 | CSR_REGISTER_BASE + CSR_BUS_MANAGER_ID, | |
292 | card->bm_transaction_data, | |
293 | sizeof(card->bm_transaction_data)); | |
294 | ||
295 | if (rcode == RCODE_GENERATION) | |
296 | /* Another bus reset, BM work has been rescheduled. */ | |
297 | goto out; | |
298 | ||
299 | if (rcode == RCODE_COMPLETE && | |
300 | card->bm_transaction_data[0] != cpu_to_be32(0x3f)) { | |
301 | ||
302 | /* Somebody else is BM. Only act as IRM. */ | |
303 | if (local_id == irm_id) | |
304 | allocate_broadcast_channel(card, generation); | |
305 | ||
306 | goto out; | |
307 | } | |
308 | ||
309 | if (rcode == RCODE_SEND_ERROR) { | |
310 | /* | |
311 | * We have been unable to send the lock request due to | |
312 | * some local problem. Let's try again later and hope | |
313 | * that the problem has gone away by then. | |
314 | */ | |
315 | fw_schedule_bm_work(card, DIV_ROUND_UP(HZ, 8)); | |
316 | goto out; | |
317 | } | |
318 | ||
319 | spin_lock_irqsave(&card->lock, flags); | |
320 | ||
321 | if (rcode != RCODE_COMPLETE) { | |
322 | /* | |
323 | * The lock request failed, maybe the IRM | |
324 | * isn't really IRM capable after all. Let's | |
325 | * do a bus reset and pick the local node as | |
326 | * root, and thus, IRM. | |
327 | */ | |
328 | new_root_id = local_id; | |
329 | fw_notify("BM lock failed, making local node (%02x) root.\n", | |
330 | new_root_id); | |
331 | goto pick_me; | |
332 | } | |
333 | } else if (card->bm_generation != generation) { | |
334 | /* | |
335 | * We weren't BM in the last generation, and the last | |
336 | * bus reset is less than 125ms ago. Reschedule this job. | |
337 | */ | |
338 | spin_unlock_irqrestore(&card->lock, flags); | |
339 | fw_schedule_bm_work(card, DIV_ROUND_UP(HZ, 8)); | |
340 | goto out; | |
341 | } | |
342 | ||
343 | /* | |
344 | * We're bus manager for this generation, so next step is to | |
345 | * make sure we have an active cycle master and do gap count | |
346 | * optimization. | |
347 | */ | |
348 | card->bm_generation = generation; | |
349 | ||
350 | if (root_device == NULL) { | |
351 | /* | |
352 | * Either link_on is false, or we failed to read the | |
353 | * config rom. In either case, pick another root. | |
354 | */ | |
355 | new_root_id = local_id; | |
356 | } else if (!root_device_is_running) { | |
357 | /* | |
358 | * If we haven't probed this device yet, bail out now | |
359 | * and let's try again once that's done. | |
360 | */ | |
361 | spin_unlock_irqrestore(&card->lock, flags); | |
362 | goto out; | |
363 | } else if (root_device_is_cmc) { | |
364 | /* | |
365 | * FIXME: I suppose we should set the cmstr bit in the | |
366 | * STATE_CLEAR register of this node, as described in | |
367 | * 1394-1995, 8.4.2.6. Also, send out a force root | |
368 | * packet for this node. | |
369 | */ | |
370 | new_root_id = root_id; | |
371 | } else { | |
372 | /* | |
373 | * Current root has an active link layer and we | |
374 | * successfully read the config rom, but it's not | |
375 | * cycle master capable. | |
376 | */ | |
377 | new_root_id = local_id; | |
378 | } | |
379 | ||
380 | pick_me: | |
381 | /* | |
382 | * Pick a gap count from 1394a table E-1. The table doesn't cover | |
383 | * the typically much larger 1394b beta repeater delays though. | |
384 | */ | |
385 | if (!card->beta_repeaters_present && | |
386 | root_node->max_hops < ARRAY_SIZE(gap_count_table)) | |
387 | gap_count = gap_count_table[root_node->max_hops]; | |
388 | else | |
389 | gap_count = 63; | |
390 | ||
391 | /* | |
392 | * Finally, figure out if we should do a reset or not. If we have | |
393 | * done less than 5 resets with the same physical topology and we | |
394 | * have either a new root or a new gap count setting, let's do it. | |
395 | */ | |
396 | ||
397 | if (card->bm_retries++ < 5 && | |
398 | (card->gap_count != gap_count || new_root_id != root_id)) | |
399 | do_reset = true; | |
400 | ||
401 | spin_unlock_irqrestore(&card->lock, flags); | |
402 | ||
403 | if (do_reset) { | |
404 | fw_notify("phy config: card %d, new root=%x, gap_count=%d\n", | |
405 | card->index, new_root_id, gap_count); | |
406 | fw_send_phy_config(card, new_root_id, generation, gap_count); | |
407 | fw_core_initiate_bus_reset(card, 1); | |
408 | /* Will allocate broadcast channel after the reset. */ | |
409 | } else { | |
410 | if (local_id == irm_id) | |
411 | allocate_broadcast_channel(card, generation); | |
412 | } | |
413 | ||
414 | out: | |
415 | fw_node_put(root_node); | |
416 | out_put_card: | |
417 | fw_card_put(card); | |
418 | } | |
419 | ||
420 | void fw_card_initialize(struct fw_card *card, | |
421 | const struct fw_card_driver *driver, | |
422 | struct device *device) | |
423 | { | |
424 | static atomic_t index = ATOMIC_INIT(-1); | |
425 | ||
426 | card->index = atomic_inc_return(&index); | |
427 | card->driver = driver; | |
428 | card->device = device; | |
429 | card->current_tlabel = 0; | |
430 | card->tlabel_mask = 0; | |
431 | card->split_timeout_hi = 0; | |
432 | card->split_timeout_lo = 800 << 19; | |
433 | card->split_timeout_cycles = 800; | |
434 | card->split_timeout_jiffies = DIV_ROUND_UP(HZ, 10); | |
435 | card->color = 0; | |
436 | card->broadcast_channel = BROADCAST_CHANNEL_INITIAL; | |
437 | ||
438 | kref_init(&card->kref); | |
439 | init_completion(&card->done); | |
440 | INIT_LIST_HEAD(&card->transaction_list); | |
441 | spin_lock_init(&card->lock); | |
442 | ||
443 | card->local_node = NULL; | |
444 | ||
445 | INIT_DELAYED_WORK(&card->work, fw_card_bm_work); | |
446 | } | |
447 | EXPORT_SYMBOL(fw_card_initialize); | |
448 | ||
449 | int fw_card_add(struct fw_card *card, | |
450 | u32 max_receive, u32 link_speed, u64 guid) | |
451 | { | |
452 | int ret; | |
453 | ||
454 | card->max_receive = max_receive; | |
455 | card->link_speed = link_speed; | |
456 | card->guid = guid; | |
457 | ||
458 | mutex_lock(&card_mutex); | |
459 | ||
460 | generate_config_rom(card, tmp_config_rom); | |
461 | ret = card->driver->enable(card, tmp_config_rom, config_rom_length); | |
462 | if (ret == 0) | |
463 | list_add_tail(&card->link, &card_list); | |
464 | ||
465 | mutex_unlock(&card_mutex); | |
466 | ||
467 | return ret; | |
468 | } | |
469 | EXPORT_SYMBOL(fw_card_add); | |
470 | ||
471 | ||
472 | /* | |
473 | * The next few functions implement a dummy driver that is used once a card | |
474 | * driver shuts down an fw_card. This allows the driver to cleanly unload, | |
475 | * as all IO to the card will be handled (and failed) by the dummy driver | |
476 | * instead of calling into the module. Only functions for iso context | |
477 | * shutdown still need to be provided by the card driver. | |
478 | */ | |
479 | ||
480 | static int dummy_enable(struct fw_card *card, | |
481 | const __be32 *config_rom, size_t length) | |
482 | { | |
483 | BUG(); | |
484 | return -1; | |
485 | } | |
486 | ||
487 | static int dummy_update_phy_reg(struct fw_card *card, int address, | |
488 | int clear_bits, int set_bits) | |
489 | { | |
490 | return -ENODEV; | |
491 | } | |
492 | ||
493 | static int dummy_set_config_rom(struct fw_card *card, | |
494 | const __be32 *config_rom, size_t length) | |
495 | { | |
496 | /* | |
497 | * We take the card out of card_list before setting the dummy | |
498 | * driver, so this should never get called. | |
499 | */ | |
500 | BUG(); | |
501 | return -1; | |
502 | } | |
503 | ||
504 | static void dummy_send_request(struct fw_card *card, struct fw_packet *packet) | |
505 | { | |
506 | packet->callback(packet, card, -ENODEV); | |
507 | } | |
508 | ||
509 | static void dummy_send_response(struct fw_card *card, struct fw_packet *packet) | |
510 | { | |
511 | packet->callback(packet, card, -ENODEV); | |
512 | } | |
513 | ||
514 | static int dummy_cancel_packet(struct fw_card *card, struct fw_packet *packet) | |
515 | { | |
516 | return -ENOENT; | |
517 | } | |
518 | ||
519 | static int dummy_enable_phys_dma(struct fw_card *card, | |
520 | int node_id, int generation) | |
521 | { | |
522 | return -ENODEV; | |
523 | } | |
524 | ||
525 | static const struct fw_card_driver dummy_driver_template = { | |
526 | .enable = dummy_enable, | |
527 | .update_phy_reg = dummy_update_phy_reg, | |
528 | .set_config_rom = dummy_set_config_rom, | |
529 | .send_request = dummy_send_request, | |
530 | .cancel_packet = dummy_cancel_packet, | |
531 | .send_response = dummy_send_response, | |
532 | .enable_phys_dma = dummy_enable_phys_dma, | |
533 | }; | |
534 | ||
535 | void fw_card_release(struct kref *kref) | |
536 | { | |
537 | struct fw_card *card = container_of(kref, struct fw_card, kref); | |
538 | ||
539 | complete(&card->done); | |
540 | } | |
541 | ||
542 | void fw_core_remove_card(struct fw_card *card) | |
543 | { | |
544 | struct fw_card_driver dummy_driver = dummy_driver_template; | |
545 | ||
546 | card->driver->update_phy_reg(card, 4, | |
547 | PHY_LINK_ACTIVE | PHY_CONTENDER, 0); | |
548 | fw_core_initiate_bus_reset(card, 1); | |
549 | ||
550 | mutex_lock(&card_mutex); | |
551 | list_del_init(&card->link); | |
552 | mutex_unlock(&card_mutex); | |
553 | ||
554 | /* Switch off most of the card driver interface. */ | |
555 | dummy_driver.free_iso_context = card->driver->free_iso_context; | |
556 | dummy_driver.stop_iso = card->driver->stop_iso; | |
557 | card->driver = &dummy_driver; | |
558 | ||
559 | fw_destroy_nodes(card); | |
560 | ||
561 | /* Wait for all users, especially device workqueue jobs, to finish. */ | |
562 | fw_card_put(card); | |
563 | wait_for_completion(&card->done); | |
564 | ||
565 | WARN_ON(!list_empty(&card->transaction_list)); | |
566 | } | |
567 | EXPORT_SYMBOL(fw_core_remove_card); | |
568 | ||
569 | int fw_core_initiate_bus_reset(struct fw_card *card, int short_reset) | |
570 | { | |
571 | int reg = short_reset ? 5 : 1; | |
572 | int bit = short_reset ? PHY_BUS_SHORT_RESET : PHY_BUS_RESET; | |
573 | ||
574 | return card->driver->update_phy_reg(card, reg, 0, bit); | |
575 | } | |
576 | EXPORT_SYMBOL(fw_core_initiate_bus_reset); |